Grade-Separated Interchange

INT-GSI-10
Intersections & Crossings

Grade-Separated Interchange

An interchange carrying conflicting movements on separate vertical levels, connected by ramps, eliminating at-grade conflict entirely. Freeway-scale only.

Typical at: Undeveloped Rural Suburban

Compact and Urban are edge cases. Core is an unlikely pairing.

#Design notes

This is an acknowledged fallback for genuinely Freeway-scale volume or speed beyond what even a turbo-roundabout can manage, not a general-purpose alternative to the Commonway System's roundabout-first intersection philosophy. It stays confined to the density range where full Freeway-scale roads themselves are realistic.

Unsourced claim

Formal citations for this pattern have not yet been compiled from primary sources.

Suggest changes to this page (opens in new tab) Last updated August 29, 2026